AN ENDLESS SCIENCE

Are you still struggling to reconcile the disparity between Darwin’s evolution theory and the Divine Creation? Perhaps most of us are recurrently, mystified about the feasibility of time travel and time machines. How about the existence of parallel universes, do you find it amazing or rather irrational? Still interested around alien invasion or you may be more engrossed reflecting the issues of global warming and its menace that we are already living through. Plus, the revolution of technology that has affected every single aspect of our life, we may continue to ask these questions: Why do we have to learn Science? Is there an end to Science?

RISE AND FALL OF STARS

Physics is so dear to me, although many students and science teachers alike do not feel good with it. To some, it is boring and full of Maths. Others just do not find it attractive to their intellect, I should say.  But to me, it is full of wonders and an endless chain of discoveries. One of my favourite topics in this field is Space and the Universe.  It appeals to me differently because I feel like watching a movie and doing some reflection at the same time.

Just like the stars that we glimpse in the sky on quite nights, they are full of excitement. They are part of the history that unfolds before our senses, because the stars that you see were actually there many years ago. Stars are light years away from the Earth, and so it would take years for its emitted light to reach us. A light year is a distance that light can travel in one year.  If a ray of light travels in a vacuum in approximately 3x10⁸ m/s, the ray of the sun which distance from the Earth is approximately 150 million kilometres could reach the Earth in eight minutes, how much more for distant stars?

They are simply stars, but it is fascinating to learn that they have a life cycle. And the process is extremely long, explosive, but amazing.  Like us, they are born, they live, and will eventually die.

ROCKS OF THE EARTH

Materials like chairs, woods, carpets, clothes, glass, metals amongst others; are materials found in or on the Earth. Chemical reactions helped manufacturers to make these raw materials become useful, attractive, and durable. The earth’s crust provides abundant amount of minerals, rocks, and fossil fuels. A mineral is a single substance, which has a chemical name and formula. A rock is a mixture of different minerals. Examples of minerals are limestone and rock salts. Their purest from are called calcium carbonate (CaCo3) and Sodium Chloride ( NaCl), respectively.


It is believed that when the Earth cooled down millions of years after the birth of the solar system, its molten crust solidified into igneous rocks. Over millions of years, the geological

FRUITY DNA EXPERIMENT

Cells are composed of nuclei, and nucleus is considered the largest single structure within the cell. It is further composed of separate structures called chromosomes which are responsible to carry information for reproduction or for sort of genetic analysis in laboratories. These chromosomes are made of a more complex polymer called DNA or Deoxyribonucleic acid. Although DNA is a very large molecule, you could not see it with your naked eye, unless you know and you have a great deal with it.


The Fruity DNA experiment will teach you the procedure how to collect large number of chromosomes using common fruits. This is just a simple laboratory experiment for a biology class.






Materials/Equipment


4 x 100ml beaker
2 x 250ml beaker
1 x 500ml beaker

SIMPLY FACTS

1. Although plants do not have nerves, they do use electrical impulses for coordination.  These impulses are like the humans, but much slower.  The Venus flytrap plant is a good example.
2. A single photon of light – the smallest quantity you can get, is enough to stimulate a rod cell.
3. Each off your fingers has about 3000 touch receptors.  This is as many as the whole of your back and chest.
4. You can survive for weeks without food, but only a few days without water
5. A healthy man should have about 15% of his weight as body fat.  A healthy woman should have about 25 %.
6. Alcohol gets from the stomach to the brain in just few minutes.
7. The heat inside the Earth is produced when radioactive substances called isotopes decay. It is not heat left over from when the Earth first formed.
8. One strand of optical fibre can handle up to 10000 telephone conversations all at the same time.

CHEMICAL CHANGES

One of the most important topics in Chemistry is chemical changes.  Students find it interesting because they get what they see; and learning is enhanced when they love what they are doing.

Teachers and students alike could try this simple yet relevant activity for chemical changes. It is always recommended that teachers are around to supervise when students are allowed to do this practical.

Theory:

            There are signs if chemical change has taken place. When one or more substances are formed out of a reaction then chemical change has occurred. In chemical change, the change is usually difficult to reverse. For example, when you cook food, chemical change happens and there is no way you could get back the original substance if you wish to. In chemical change, energy is taken out or given in. Just like, when iron reacts with sulphur; heat is produced. When there is a chemical reaction, the atoms are rearranged so they mixed in an entirely different way.

HOW TO DILUTE HYDROCHLORIC ACID (HCl)

The instructions below are only good for concentrated Hydrochloric from 

35-38% solution with a specific gravity of 1.18 and a molar mass of 36.46 g/mol.

The concentration of Hydrochloric acid decreases over a long period of time; as the gas diffuses into the atmosphere. It is advisable to keep stocks in secured glass containers and should be kept properly inside the laboratory. It is best to store them in an outside stock room if there is any in your school.

Do not attempt diluting Hydrochloric acid if it is your first. Ask a colleague or from a more experienced laboratory staff to help you. Do not allow students to dilute concentrated solutions, but you can demonstrate this in the science laboratory in order for them to understand the procedure correctly. However, you may ask them to dilute further diluted solution from 1M and lower.

FERMENTATION ACTIVITY

This practical can be done as a demo or class experiment provided you have enough materials for the whole class.


Fermentation is the process of breaking down of food by micro-organisms using anaerobic respiration. Yeast is a single-celled fungus, and reproduces by growing buds out of the cell and feeds itself on sugars like glucose. In the process of fermentation, the yeast makes alcohol (Ethanol) and carbon dioxide. To illustrate it better, consider the equation below


The Equation:


GLUCOSE --> ETHANOL + CARBON DIOXIDE

LET’S BURN YOUR MONEY

What? That sounds insane, but remember there is a load of crazy stuff in science that we can learn and enjoy from. I do not mean burning your money is fun, neither I would give in to the challenge if I am not confident I could actually have it back in exactly the same condition as it should be. You can practice this using ordinary white paper or filter paper cut into note-like sizes, that is to build up your confidence that it truly works. So, have fun and burn your money away.

COLOURFUL CRYSTAL GARDEN

Recently, I talked about demonstrating firework effects using common salt compounds available in our chemistry laboratory.  These compounds can also be used to make other exciting science activities like the COLOURFUL CRYSTAL GARDEN.

This is a simple, but exciting practical/demo that teachers can do in the laboratory.  Again, just be careful with the salt compounds for they maybe corrosive, irritant, or toxic.

Before you start, you need to secure the following things:

SODIUM SILICATE ( commonly called WATER GLASS)

WATER

SALT COMPOUNDS

HYDROGEN BALLOON

Let us get some basic stuff together and make a hydrogen balloon to demonstrate in the class. The main idea is to collect hydrogen gas from an acid-metal reaction and show the students the safest way to do it.

CHEAPER LAVA LAMP

As much as possible, science teachers would want to do activities in the class, which are exciting but less expensive. Especially when the kids are asked to bring the materials needed and turned out to be difficult to find or too much for the wallet, the thrill to do it would eventually fade.

There are many lava lamps available in the market but why not make your own and use of materials that one can easily grab in the cupboard or take out from the medicine drawer or buy from the nearest supermarket. Today I am sharing to you how to make a LAVA LAMP which I have done myself several times in science club activities or classroom demonstrations.

MAKING and TESTING ELECTROMAGNETS

There is a very practical and simple way to make and test electromagnets in science laboratory. After you are done discussing the theory of electromagnets, it is time to allow students some hands-on activities, to thoughtfully remember the concept. This is not a grand experiment though, but at least your high school students could look into how and what are the necessary materials needed to make a simple electromagnet, and test its strength afterwards.

HIGH tide and LOW tide AGAIN?

Many students would still find it confusing to understand the phenomenon of high tide and low tide.  What causes it and why?

Simple reason is to associate it to gravity of the Earth and the Moon, and the pull of force is called gravitational force. Gravitational force exists between two objects with mass.  For smaller objects, this force is not very noticeable. However, for massive objects like the planets, this gravitational force creates a significant effect. Both the Earth and the moon exert a force towards each other. The gravitational force decreases with increasing distance, so the water nearest the moon is pulled more strongly towards the moon than the mass of the Earth itself.  This force causes the water of the earth to swell on the area directly opposite the moon –which is called HIGH TIDE.

FIREWORKS AT WORK

There is a more interesting activity to explain how fireworks are made, without actually exposing the students to greater risk. ( I have to say greater because there is still a risk doing this practical.) How do fireworks create that spectacular fountain of colours and amazed young and old alike. The gorgeous exploding mixture of purples and reds, blues, yellows, greens, lilac, is just a salt away. Chemistry has loads to offer when it comes to interesting activities, and this is one of those.

SIMPLE EXPERIMENT: LAW OF REFLECTION

This activity investigates the rule of reflection, which focuses on obtaining, collecting, and considering evidence. The students should learn and remember the basic terms that are associated with the law of reflection.

When you look in a mirror, you can see a reflection of yourself.  If you look at texts on the newspapers or magazines, they appear to be reversed, which is the way light is reflected by a mirror. How can we investigate this phenomenon? What is reflection? What is the law of reflection?

In this practical, you need plane mirrors, concave, and convex mirrors.  Your focus is on making measurements accurately, recording the results, and making conclusions from the evidence collected.

CONDUCTION, CONVECTION, and RADIATION

Many practical classroom activities could be carried out, when teaching the concepts of conduction, convection, and radiation. These are simple yet relevant, and would allow students to understand the topic easily. The concept has to be taught in the first 15 minutes of the 1-hour class and then proceed to show some of these demos.

The teacher prepares the materials needed and see to it that safety precautions are observed.

USEFUL INFRA-RED

The sun is a primary source of the Earth’s energy.  In fact, the energy to heat us up travels from it at the speed of light, just like the light rays.  This particular energy rays that cause the most heating are called infra-red rays.  These are also light rays but of longer wavelength. Since it is a light ray, it can also be reflected by mirrors. This is where the idea of ‘solar furnace’ comes about, particularly in hotter parts of the world where solar furnace is used, to collect the rays from the sun and focus them on to kettles or cooking pans.

Activity

On a sunny day, take a concave mirror outside to heat a spoonful of water.

OR

Take the same concave mirror outside to light a match. It would help better if you first blacken the head of the match with a pencil.

Note:

Be very careful in conducting this practical.

HOW TO COLLECT and TEST OXYGEN, HYDROGEN, and CARBON DIOXIDE

One of the most challenging tasks of a science teacher in a chemistry class is how to show that gases exist and it can be collected from simple reactions. Most common amongst these gases are OXYGEN, HYDROGEN, and CARBON DIOXIDE.

WHY THE SKY IS BLUE?

The sky is blue especially during bright days due to Rayleigh scattering. This scattering is the elastic scattering of electromagnetic radiation including light, by particles much smaller than the wavelength of the light. It can happen notably when light travels through gases or air. Rayleigh scattering of sunlight results in diffuse sky radiation, which is primarily the reason why the sky is blue and the sun look yellow.